In our day-to-day life, we see a lot of data around us, be it on TV, phone, or any other medium. It is always there in the form of facts and information, like the average run rate of a cricket player. We may choose to ignore all this information, but sooner or later we will have to learn the art of forming statistics. In class 10 maths chapter 14 statistics, we will learn how to organize data according to our need to extract meaningful information marking a stepping stone to master the art of statistics.

In this digital era, the importance of data and statistics has skyrocketed. Big organizations and companies love to hire people who know their way around statistics. This is why chapter 14 is of great importance from a career point of view.

## Class 10 Maths Chapter 14 Statistics

We have learned a lot about statistics in the previous class, and we will learn a lot more in class 10th as well. But, to make the learning experience smooth and easy, we must first recall the important points and terms that we have learned about statistics in the previous class.

**Data & its types**

According to NCERT, facts or figures, collected with a definite purpose, are called data. To understand this, let’s assume that you want to see how have you performed in all your classes, from class 1st to 9th. To do so, you will have to compare the percentages of all your classes. So, the percentage that you collected to compare will be called data.

Raw data: raw data is data that is not organized. We know that data is collected for specific reasons, we want to achieve something by reading the data, but to read the data we first need to organize it in a manner so that it can make some sense. So, unless the data is organized in a particular fashion, it is called raw data.

Primary data: When the data is collected for a definitive objective, then it is called primary data. Like, in the above example, you collected the percentage of all your classes for the definitive objective of comparing your performance, therefore, it is primary data.

Secondary data: The data that is collected from different sources who collected that data for other objectives is called secondary data. e.g continuing with our above example, imagine that you have misplaced some of your old class mark sheets, but your mom remembers all your percentages. Now, you are not getting the information directly yourself, your source of information is your mom and you will have to rely on the data that she will give you, and it may be inaccurate.

**What is statistics?**

In class 10 maths chapter 14 statics is the extraction of meaningful information from the data collected. We collect data, then analyze it, interpret it, and then present it in a readable form. Doing all this is all part of statistics.

Data table: When we present the data in a tabular form, then that table is called a data table.

Range & Frequency: The difference between the highest and the lowest values in the data is called the range of the data. The number of times a certain observation occurred in the data is called the frequency.

### Class 10 Maths Chapter 14 Statistics

Buildings that have strong foundations stand unshaken by any test, the same is true for learning, if your foundation for a topic is strong then you can thrive in any exam. This is why at CBSE blueprint, we insist on clearing basics first. Let’s continue with basic terms of statistics.

Ungrouped frequency distribution table: When we simply write the value and the number of times that value is repeated in a table, then it is called the ungrouped frequency. e.g let’s say that you scored 66% 4 times and 69% 2 times in all your classes, and in this order, you will write all your percentages in a table i.e number of times you have scored the same percentage. You have just prepared an ungrouped frequency distribution table.

Grouped frequency distribution table: In this, we create a group of values and the sum of the frequencies of all the values in that group becomes the frequency of that group. e.g instead of writing 66% and 69% separately, you create a group of 65-70%. Since you have scored 66% 4 times and 69% 2 times, therefore the frequency of this group will be 4+2 = 6. Grouped frequency gives a quick overview of data, and in-class 10 maths chapter 14 statistics, we will learn this topic extensively.

Class-intervals: The groups that you just created in the above example are called classes or class intervals. So, classes are simply the groups that hold many values under them. e.g in the above example, the group 65-70% is a class or class interval.

Class-size or class width: The size of a group or class is called the class size. e.g the class size of 65-70% is 5.

Lower class limit: The lower value of a group or class is called the lower class limit. e.g 65% is the lower class limit in class 65-70%.

Upper-class limit: The upper value of a class is called the upper-class limit. e.g 70% is the upper-class limit of class 65-70%.

#### Class 10 Maths Chapter 14 Statistics

Ungrouped Data: It is simply unorganized data. When we collect data but do not organize it in any fashion to make a meaningful interpretation from it, then it will be called ungrouped data.

Grouped data: when data is organized to extract some meaningful insight from it, then it is called grouped data.

Mean: It is the sum of the values of all the observations divided by the total number of observations. So, if you have 4 observations say 6, 7, 8, & 9, then the mean will be (6+7+8+9)/4.

Median: The value which divides the number of observations into two parts is called the median of the observation.

Mode: The observation with maximum frequency is called the mode.

Finally, we are through all the basic terminologies that are needed in class 10th maths chapter 14 statistics. Now let’s proceed to the topics of the chapter.

In class 9th we learned to calculate the mean, median, and mode of ungrouped data. But in class 10th, we will learn how to calculate: mean median and mode of grouped data.